The incidence of obesity worldwide continues to escalate with the spread of the Western diet and with it there has been a corresponding increase in numerous obesity-related disorders. Of all the causes for obesity, the predominant one seems to be choice - the choice to eat more and exercise less. One of the choices that has been linked with obesity has been the selection of a high fat, calorically dense diet. Recent research has shown that fatty acids are the prototypical fat stimulus in the gustatory, digestive, somatosensory and central nervous systems. This proposal seeks to follow up on interesting observations that show in mice deletions in important elements in the fatty acid signaling pathway lead to decreases in fat intake and concomitant reductions in body weight and body fat. In this two year exploratory proposal we will attempt to discern (1) the effect specific fatty acid signaling components have on dietary fat intake and body composition; (2) whether pre- or post-ingestive signaling contributes to the control of fat intake and (3) the nutrient specificity of an changes in food intake associated with aberrant fatty acid signaling. Understanding the role of chemosensory signals in the control of nutrient intake is poorly understood and the finding that alterations in a specific chemosensory pathways alters dietary fat intake remains highly novel and potentially important for the control of dietary-induced obesity.